Gas Pool Heaters: Cost, Heat Time, Common Problems & Lifespan

Gas pool heaters are the fastest way to heat a swimming pool or spa, making them ideal for quick temperature boosts, year-round spa use, and cooler-season swimming. They use either natural gas or propane to rapidly heat water as it passes through the heat exchanger. This guide answers the most common questions about gas heater costs, warm-up time, shutdown issues, efficiency, and replacement timing.

Quick Gas Pool Heater Diagnostics Checklist

You may have a gas pool heater problem if you notice:

• Heater won’t turn on

• Heater turns on then shuts off

• Water is not warming

• Error codes on display

• Strong gas smell

• Soot or black residue

• Rust or water leaking from heater

⚠️ If you ever smell strong gas, turn off the heater immediately and call a professional.

Why Is My Gas Pool Heater Not Turning On?

The most common causes include:

• No gas supply

• Tripped breaker or blown fuse

• Dirty or failed igniter

• Faulty pressure switch

• Low water flow

• Bad control board

• Safety sensors preventing ignition

Modern heaters have multiple safety systems that will block ignition if any condition is unsafe.

How Long Does It Take a Gas Heater to Heat a Pool?

Typical heating speed:

• Small pool: 1–2 hours

• Medium pool: 2–4 hours

• Large pool: 4–8 hours

Gas heaters raise water temperature 8–12°F per hour, making them much faster than heat pumps.

Why Does My Pool Heater Keep Shutting Off?

Common shutdown causes:

• Low water flow

• Dirty filter

• Air in the plumbing

• Faulty pressure switch

• Overheating from scale buildup

• Gas pressure issues

• Internal sensor failure

Repeated shutdowns indicate a circulation, gas, or internal safety fault.

Is It Expensive to Heat a Pool With Gas?

Gas heaters are:

• ✅ Fastest heating option

• ❌ Most expensive to operate long-term

Typical monthly cost varies widely depending on:

• Pool size

• Desired temperature

• Outside air temperature

• Gas prices

• How often the heater runs

They are ideal for occasional heating, not constant temperature maintenance.

How Long Do Gas Pool Heaters Last?

Average lifespan:

• 7–12 years with proper maintenance

• Shorter lifespan if:

  • Water chemistry is poor

  • Calcium scale builds inside the exchanger

  • Heater is exposed to salt air without protection

  • Heater runs constantly

Most Common Gas Pool Heater Problems

• Failed igniter

• Dirty flame sensor

• Scaled heat exchanger

• Rusted internal headers

• Faulty control board

• Pressure switch failure

• Improper gas pressure

Many of these problems are triggered by poor water chemistry and restricted flow.

Gas Pool Heater vs Heat Pump (Quick Comparison)

Gas Heater:

• ✅ Heats very fast

• ✅ Works in any weather

• ✅ Ideal for spas

• ❌ Higher operating cost

• ❌ Shorter lifespan

Heat Pump:

• ✅ Lower operating cost

• ✅ Great for maintaining temperature

• ✅ Longer lifespan

• ❌ Slower heating

• ❌ Less effective in cold weather

When Should You Repair vs Replace a Gas Pool Heater?

Repair If:

• Igniter or sensor failure

• Pressure switch issue

• Minor gas valve or wiring issue

• Heater is under 7–8 years old

Replace If:

• Heat exchanger is cracked or leaking

• Internal rust damage is severe

• Control board failure on older unit

• Heater is 10–12+ years old

• Repair exceeds 50% of replacement cost

How to Extend the Life of a Gas Pool Heater

• Maintain perfect water chemistry

• Keep filter clean for proper flow

• Install a sacrificial anode (if recommended)

• Protect heater from salt spray and rain

• Perform yearly professional inspections

When to Call a Professional for Gas Pool Heater Problems

Call a professional immediately if:

• Heater will not ignite

• Heater shuts off repeatedly

• You smell gas

• Heater leaks water or rust

• Error codes appear

• Water temperature won’t rise

Gas heaters involve high voltage, combustion, and pressurized gas — DIY repair is dangerous.

Gas Pool Heater Repair & Installation in Peoria, AZ

If you’re in Peoria or the West Valley, Triton Pools offers full gas pool heater services:

• Heater diagnostics

• Igniter & sensor repair

• Gas pressure testing

• Control board replacement

• Heat exchanger inspection

• New heater installation & upgrades

Schedule your gas pool heater service with Triton Pools today.

FAQ: Gas Pool Heaters

Do gas pool heaters work in winter?
Yes. Gas heaters work in cold weather far better than heat pumps.

Can I leave my gas heater running all the time?
You can, but it is very expensive. They are best used for quick heating.

Do gas heaters work for hot tubs and spas?
Yes — they are the best option for rapid spa heating.

Does poor water chemistry damage gas heaters?
Yes. High calcium, low pH, and poor sanitation rapidly destroy heat exchangers.

Is propane more expensive than natural gas for pool heaters?
Yes. Propane typically costs more per BTU than natural gas.